Cultivated land serves as the material foundation for human survival and development. The construction of high-standard farmland is a crucial measure to enhance grain production capacity and ensure national food security. The evaluation of cultivated land quality grades is an important means to improve land management and protection intensity. This study employs the concept of fuzzy mathematics, utilizing methods such as the membership function method and expert experience method to standardize the evaluation factors. It investigates and evaluates the quality of cultivated land before and after the high-standard farmland construction project in four townships of Yuanping City in 2021. The results showed that the content of organic matter, available phosphorus and available potassium in the project area increased by 7.45%, 9.59% and 6.48%, respectively. The average grade of cultivated land quality after construction was 5.73, which was 0.54 higher than that before construction. To a certain extent, the high-standard farmland construction project has enhanced the quality level of cultivated land and the grain production capacity in Yuanping City.